WRN and systemic sclerosis: Previous studies show that repair proteins implicated in the DSB/R mechanism are targets for autoantibodies, including Ku, the poly(ADP-ribose) polymerase (PARP), the Meiotic Recombination 11 Homolog (Mre11), the Werner Syndrome RecQ Like Helicase (WRN), and the Poly(ADP-Ribose) polymerase (PARP), which are found in patients with SSc (43).